GPB zones as a precursor for S{prime}precipitation in Al-based matrices

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:468956

Radmilovic, V; Ratkovic, S ^[1]; Shiflet, G J ^[2]; Dahmen, U ^[3]

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1. Univ. of Belgrade (Yugoslavia)
2. Univ. of Virginia, Charlottesville, VA (United States)
3. Lawrence Berkeley National Lab., CA (United States)

In the pseudo-binary Al-Al{sub 2}CuMg alloy, the Cu/Mg-rich precipitation zones (GPB) are able to cause considerable hardening of the matrix. The hardening is apparently not very sensitive to the zone size or degree of ordering. According to Silcock these zones are cylindrical, 1-2 nm in diameter and 4 nm long. They are also formed during the early stage of aging of 190{degrees}C and are followed by nucleation of S{prime} precipitates with (210) habit plane. Overaging occurs by the further formation and growth of S{prime} with a corresponding re-solution of GPB zones. Since the discovery of GP zones (reach in Cu) in Al-Cu alloys by Guinier and Preston, the structure of these zones, even at atomic level, has been studied extensively. However, there are very few studies of GPB zone structure and crystallographic relationship with Al matrix. In this paper results using atomic resolution electron microscopy on the GPB zone size, structure and crystallographic orientation relationship with Al matrix are reported.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 468956
• Report Number(s): CONF-960877--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
COPPER ALLOYS
IMAGES
MAGNESIUM ALLOYS
PRECIPITATION HARDENING